Embodiments of the invention relate to the field of portable digital devices and more specifically to multifunction portable digital devices having image-handling functions.
Some mobile devices contain gyroscopes, compasses, GPS capabilities, cameras and image-processing functions that allow them to be used for augmented reality applications. An augmented reality application is one that overlays virtual computer-generated imagery over a real-world image of the environment. In an example, a camera in such a device may be pointed at a building having historical significance. The device may use GPS and other data to identify the building and may then seek historical data relating to the building and display the data as text overlaid on the bottom of the image displayed on the display screen of the device. Augmented reality may thus enrich the user's experience of the view of the building.
Augmented reality applications rely on the user pointing the mobile device's camera at the area of interest, often leveled on a horizon, in order to have useful computer-generated imagery placed on top of the displayed image. Typically mobile devices use the camera at the back of the device (the side opposite to the side bearing the display), thus requiring users to hold the device vertically in front of them, at approximately eye-level. This feels very unnatural and is particularly difficult to do when walking. As many augmented reality applications are intended to operate as guides to scenes through which a user is walking while looking, for example at the architectural features of buildings in a street, this limitation is quite severe.